Production of cement.



' chamber or m the clinker produced BERN-HARD GRAU, KRAQ ZWIEOK, NEAR STETTIN, GERMANY;

PRQDUCTHON OF GEM ENT- Specification of Letters Patent.

Patented Feb. 27, 1906.

Application filed 3m 21. 1904. Serial No 213,541.

To alt whom it may concern.

Be it known that I, Enemies]: GRAU, a subject of the German Emperor, and a resident of Kratzwieck, nee-r Stettin, Germanjghave invent-ed an imnrovement in the Production of Cement, of which the following is a specification.

r My invention consists of an improved, simlo, and efficient method of producing hyraulic cement from blast-furnace slag.

In carrying out my invention I treat the hot slag as it comes from the blast-furnace, so that I avail myself of the heat of the hot mass in the production-of the cement and so avoid having to independentl heat the sla specially for the purpose. T e jet of fluid s ag as it runs from the blast-furnace is treated with steam bfy blowing a jet of steam against the jet 0 slag-say at right angles to it, This may be done either in a closed an open space. Dry superheated steam is most suitable for the "purpose. I find it to be suitable and effective to so regulate the force of the jet of steam in proportion to the strength oi the jet of slag that the latter is chan ed by the steam into clinkers of a granulated character. Through this treatment with steam the fluid slag undergoes chemical and physical changes and takes on other qualities of sue -a kind that by the steam when ground to the fineness of powder produces a cement powder which when treated with wa-- ter' shows the same hardening capabilities which are found in-the ordinary Portland cement of commerce.

ment which has the properties of a good Portland cement.

The cement produced thus, oor in lime, may be placed on the market either alone or ground up with other cements or cement clinkers which are richer in lime.

I claim as my invention s an improvement in the mode of producing cement from molten slag, the method herein described of blowing a sufficiently strong and violent jet of so erheated steam against a jet of the molten b est-furnace slag that the thus-divided slag is driven oii by the steam-jet so as to form a heap of, slag and in allowin this mass to cool in itself Without artificia means, thereby enabling the heat of the slag to act on the mass during its cooling, and then grinding this mass to powder, as and for the purpose described In testimony whereof I have name to this specification in the two subscribing witnesses.

crann es GRAD" signed my presence of Witnesses:

Agarnon BRANDT, v liens HILnEBnann, 

